The present invention relates to a motor speed control apparatus, and more particularly to a motor speed control apparatus which is well-suited for achieving quick response in a digital control.
A motor speed control apparatus, for example, has been disclosed in Japanese Laying-open of Patent Application No. 57-78384 (1982) entitled "Digital Control Apparatus for D.C. Motor" published in May 17, 1982.
This is concerned with a motor speed control apparatus which controls the speed of a motor by pulse signals given to gates of thyristors. The pulse signal corresponds to an ignition phase angle which is decided by a predicted value calculated in accordance with a relationship using armature currents of the motor in a certain sampling point of time and the past two sampling points of time for preventing speed control delay of the motor based on a calculating period of the control apparatus.
However, this prior art does not disclose how to determine an ignition control angle by predicted motor speed based on a plurality of motor speeds.